This invention relates to a process for producing oxide fibers and more particularly relates to a method for producing polycrystalline oxide fibers from basic aluminum chloride, zirconium acetate, zirconium oxychloride or mixtures thereof and the resulting fibers.
It is known in the prior art that certain oxide precursors may be dissolved in liquid and spun to form a fiber and the resulting fiber heated in an oxygen containing atmosphere to form an oxide fiber. For example, basic aluminum chloride may be dissolved in water and the resulting solution spun to form a basic aluminum chloride fiber which upon heating converts to a polycrystalline aluminum oxide fiber. Difficulties were encountered in prior art processes for the manufacture of polycrystalline oxide fibers. In particular, it was frequently not possible to dissolve sufficient oxide precursor in the liquid without obtaining viscosities which were too high for spinning. The dissolving of insufficient oxide precursor in the spinning liquid results in a solution which yields inferior fibers, if any.
Prior art polycrystalline fibers had insufficient strength and flexibility for many applications.
In the prior art, it was found that the addition of acetic acid to the spinning liquid substantially reduced its viscosity; however, the resulting fiber was still too brittle for many applications.